Pointing devices such as a mouse or a track ball, are well known, and with state of the art computer systems using graphical user interfaces, next to the keyboard, such pointing devices are the main input devices for operating the computer system. Typically pointing devices such as a mouse or a track ball include at least one sensor for sensing data representing displacement information in at least two spatial coordinates. A typical low cost computer mouse may include one sensor for both of the at least two spatial coordinates. In more modern pointing devices, such as an optical mouse or an optical track ball, consecutive images of a surface on which the mouse is moved on, or the surface of a ball in the mouse or the track ball, are analyzed and compared, and the displacement information in at least two spatial coordinates is derived from comparing consecutive images.
While the above pointing devices have become widely accepted for state of the art computer workstations, improvements of such devices are mostly focused on their reliability and the production costs. However, the basic functionality, namely providing software applications running on a computer workstation with displacement information in at least two spatial coordinates, has not been revised since the first pointing devices have been conceived.